JPS58145805A - Controller for moisture separating reheater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a moisture separator reheater control device for controlling the operating status of a moisture separator reheater installed in a nuclear power plant or the like.

[Technical background of the invention]

In nuclear power plants, the pressure and temperature of steam released in the reactor are considerably lower than in thermal power plants due to the performance of the reactor. Therefore, the steam led to the steam turbine is already 0.2
Contains about 0.4% moisture. If this steam is expanded to the turbine outlet pressure without moisture separation, the humidity of the steam at the final stage outlet of the low pressure turbine will reach approximately 25-4. .

If a turbine is operated using this steam, the turbine rotor blades will be significantly eroded by the moisture in the steam, and the internal efficiency of the turbine will be significantly reduced.

In order to effectively remove the moisture generated during the expansion of this steam, moisture separators have traditionally been used.In recent years, in addition to moisture separation, steam has been reheated to increase the efficiency of low-pressure turbines. For this reason, a moisture separator reheater equipped with a reheating section is used.

This moisture separation reheater is usually installed between a high-pressure turbine and a low-pressure turbine, and separates the moisture from the humid steam discharged from the high-pressure turbine into dry steam. The steam is reheated using extracted steam from the high-pressure turbine or steam from the main steam twin as a heat source, and the reheated steam is supplied to the next low-pressure bin.

[Problems with background technology]

However, if the operation of a power generation plant using a moisture separation and reheating steam turbine cannot be properly controlled in accordance with the fluctuations in the power generation plant, the following problems will occur.

α) During the speed-up process of the steam turbine, when reheated steam flows from the moisture-4 reheater into the low-pressure turbine, vibrations occur in the low-pressure turbine due to friction between the rotating part and the stationary part.

(2) The stationary part of the low-pressure turbine is heated unevenly by the reheated steam, causing thermal stress to each component of the low-pressure turbine.
Distortion etc. will occur.

(3) When high-eating reheated steam is supplied during low load, the low-pressure turbine is heated unevenly, causing an overheating phenomenon in the rotor blade row near the exhaust end.

These are caused by the supply of reheated steam to the low-pressure turbine, which is deemed necessary depending on the operating conditions of the steam turbine.

[Purpose of the invention]

The present invention aims to remove moisture by straining the reheated steam so that the state 11 of the reheated steam sent out from the moisture separation reheater always matches the state of the reheated steam required depending on the operation mode of the steam turbine. It is an object of the present invention to provide a moisture separation reheater control device that can operate a separation reheater. and a detector that detects the state of the heating steam that heats the reheating steam, and from the information obtained from both of these detectors, the state of the reheated steam 11 is maintained in a constant state required according to the operation mode of the steam turbine. It is formed by providing an arithmetic controller that fully opens and closes a regulating valve that controls the flow rate of heated steam.

In the present invention, heated steam is first fed to the reheating section of the moisture separation reheater through a regulating valve, and the reheated steam is sent out from the reheating section. The state of this reheated steam is detected by a detector and compared with the required state in an arithmetic controller. This arithmetic controller also determines the relationship between the state of the heated steam and the state of the reheated steam, and if there is a difference between the current state of the reheated steam and the required state, the difference is eliminated ( Change the valve opening of the regulating valve so that

In this way, constant reheat steam is obtained.

[Embodiments of the invention]

Examples of the present invention will be explained with regard to the first and second causes.

In FIG. 1, reference numeral 1 indicates a main steam line, and this main steam line 1 is connected to a high pressure turbine 2. In FIG. A low-pressure turbine 3 and a generator 4 serving as a load are uniaxially connected to the high-pressure turbine 2. The exhaust line of this high pressure child turbine 2 is heated by the moisture separating section 5 of the moisture separating reheater 5.
[And the reheating section 5b are connected in this order. In this moisture separation section 5a, the moisture of the wet steam sent through the exhaust line is removed, and the moisture is sent out as dry steam. This dry steam is heated in the reheating section 5b by heating steam fed through the heating steam line 21,
It becomes reheated steam and is sent to the reheated steam supply line 22,
It is fed into the low pressure steam turbine 3.

The device of the present invention is formed in this way for moisture separation and reheating! 65.

That is, the heating steam line 4 is provided with a regulating valve 7 that controls the flow rate of the heating steam. Further, in order to detect the state of the heated steam, a heated steam state detector 9 is provided in the heated steam line 21, and in order to detect the state of the reheated steam, the reheated steam supply line A reheat steam condition detector 10 is provided at 22 . In this embodiment, both detectors 9 and 10 are pressure gauges in order to detect the state of the steam based on the steam pressure. Then, one heated steam state sensor SS emits a heated steam state signal 11 (in this embodiment, a pressure signal), and the other reheated steam state detector 10
is the reheat steam status signal 14 (in this embodiment, the pressure signal) f:
emanate. In addition, by receiving the signals 11 and 141 from both sides, the current state of the reheated steam wAt- is known, and the state of the reheated steam is made to match a certain state, that is, a necessary state determined by the rolling path of the steam turbine, etc. An arithmetic controller 8 is provided which opens and closes the regulating valve 7 so as to maintain the same.

As shown in FIG. 2, this calculation controller 8 is formed by a heating steam side function calculation g12, a reheating steam IIIrJA number calculation section b1, a pressure change rate calculation section 16, a control loop switching section 13, and a general calculation section 19. ing.

The heated steam side function calculation section 12 sends the heated steam state signal 11 sent thereto as a heated steam enthalpy signal 17 to the control loop switching section 13 . The reheat steam side function calculation unit 15 sends the received reheat steam state signal 14t to the control loop switching unit 13 as a reheat steam enthalpy signal 18. The pressure reformation rate calculation unit 16 receives the reheated steam status signal 14 sent to it.
By differentiating the change in time, the pressure conversion switching valve 13 calculates the preset value 5ET-1 and the reheat steam enthalpy signal 18.
"When signal 18<value 5ET-IJ, the heated steam enthalpy signal 17t-is sent to the general calculation unit 19 as an output signal," and "when signal 18≧value 5ET-IJ, the reheated steam enthalpy The signal 18 is sent as an output signal path to the general calculation section 19. This general calculation section 19 receives the output signal word of the control loop switching section 13 and a preset value 5ET-2.
When the output signal path is small, an output signal 25 that opens the regulating valve 7 is generated, and the output signal is increased by 5ET-.
If it is equal to 2, output signal 5 is issued to maintain the current opening of regulating valve 7t, and if the output signal path is small, II
IIJ! ! 1 valve 7t - generates an output signal 5 that causes it to close.

Since the pressure change rate signal 5 is fed back to the general calculation unit 19, the output signal 5 changes as the state of the reheated steam changes, and the control loop switching unit 13
The output signal is made to match the value 5ET-2.

Both preset values 5ET-1 and 5ET-2 are values that indicate the state of reheated steam required depending on the operating mode of the steam turbine. These values 5ET-1,
5ET-2 is preferably set to change according to changes in driving mode, etc.

Next, the operation of this embodiment will be explained.

When the moisture separation reheater 5 starts operating, the pressure of the heated steam guided as a heat source through the heated steam line 21t to the reheat section 5b is measured by the heated steam state detector 9, and the heated steam state signal 11 is detected. It is sent to the heating steam side related section of the arithmetic controller. At the same time, the pressure of the reheated steam flowing through the reheated steam supply twin n is measured by the reheated steam state detector 10 and sent as a reheated steam state signal 14 to the reheated steam side calculation section 15. And both arithmetic units 12 and 15
, the enthalpy based on the saturation temperature is determined from the signals 1.14, which are pressure signals, respectively, and a heated steam enthalpy signal 17 and a reheated steam enthalpy signal 18 are generated. Next, in the control loop switching unit 13, if the reheated steam enthalpy signal 18 is smaller than the value 5ET-1, that is, if the state of the reheated steam has not reached a predetermined state, the heated steam enthalpy signal 17 is changed. output, signal 1
7 reaches the value 5ET-1, the reheat steam enthalpy signal 18 is output.

Next, in the general calculation section 19, the control loop switching section 13
The output signal is compared with the value 5ET-2, and the control valve 7 is opened when the output signal is smaller than the value 5ET-2, taking into consideration the pressure change rate signal 23 of the reheated steam which is the phytobatter signal. , the output signal 4 closes the regulating valve 7 when it is larger, and turns it off to the regulating valve 7' when it is equal.
sent to. As a result, the regulating valve 7 is operated to open and close.
The state of the reheated steam is always maintained in a state suitable for the operation mode of the steam turbine or the like.

It should be noted that each steam temperature may be used as a parameter for detecting the state 11 of the heated steam and reheated steam. driving mode,
Turbine rotation speed, main steam pressure, etc. may also be used.

〔Effect of the invention〕

The device of the present invention can reliably match the state of reheated steam with the required state, and the operation for this matching can be performed automatically, and further, reheated steam in an appropriate state can be obtained. It is possible to prevent Q effects such as vibration, thermal stress, distortion, and overheating phenomena that occur when the moisture separator is not used, and it is possible to increase the efficiency and reliability of the moisture separator and reheater, as well as the power plant. play.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a power plant equipped with the moisture separator reheater control device of the present invention, I! FIG. 2 is a boot star diagram showing the arithmetic controller. 5-moisture separation reheater, 5b-reheat section, 7-v4 valve regulator, 8
- Arithmetic controller, 9 - Heating steam condition detector, 10 - Reheating steam condition detector, 11 - Heating steam state signal, 14 - Reheating steam condition signal. ″ Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] 1. A regulating valve that controls the amount of heated steam supplied as a heat source to the reheating section of the moisture separation reheater, and a heated steam type m* that detects the state of this heated steam. a reheated steam state detector that detects the state of the reheated steam sent out from the reheating section and issues a reheated steam state signal;
From the heating steam status signal and reheating steam status signal, reheating black air I! a controller for opening and closing the regulating valve to maintain a constant state. 2. Claim 1: The heating steam state detector detects the heating steam pressure as the heating steam state, and the reheating steam state detector detects the reheating steam pressure as the reheating steam state. Moisture separation reheater control device as described in .